SARS-CoV-2 Infection of Vero E6 and Calu-3 Cells

Vero E6 and Calu3 2b4 cells were infected with SARS-CoV-2 according to standard protocols described previously (9 (link), 44 (link)). Briefly, growth medium was removed, and cells were subsequently infected with SARS-CoV-2 at a multiplicity of infection (MOI) of 0.01 diluted in 100 μl of PBS. Cells were then incubated for 45 minutes at 37°C and 5% CO₂. After incubation, the inoculum was removed, cells washed three times with PBS, and fresh growth medium returned. For inhibitor experiments, Calu-3 cells were pretreated with 1–100 μM kenpaullone (Sigma-Aldrich #422000) in growth media for 1 hour at 37°C. Cells were then infected with SARS-CoV-2 at an MOI of 0.01 for 45 min at 37°C and 5% CO₂. Inoculum was then removed, cells were then washed three times with PBS, and fresh growth media with kenpaullone added.